How To Clean Pool Steps That Are Yellow (Ultimate Guide)

The appearance of yellow stains around your pool steps may indicate that something is going on with your pool water chemistry.

To keep your pool water as clean and healthy as possible, proper diagnosis and prompt treatment of the problem are necessary. Yellow discolorations usually point to algae growth or iron deposits.


How To Clean Pool Steps That Are Yellow

How To Remove Yellow Stains From Pool Steps

If the pool steps turn yellow, you may have mustard algae. Mustard algae generally grow in the shade and can also adhere to the sides and bottom of the pool. Read Can you swim in a pool with mustard algae?

It is one of several different types of algae found in pools, and when the slippery substance forms on the steps, it is a tremendous climb in and out of the water.

Determine if this is the cause of the yellow hue when trying to remove yellow stains. If they disappear with scrubbing but return in a few days, mustard algae are the culprit.

Sometimes loosen the algae with a brush and then surprise the pool to fix the problem.

Otherwise, visit your local pool supply store and pick up an algaecide. Keep your filter running at all times and keep your pool water at proper pH and chlorine levels.


  • Mineral Buildup

When there is too much mineral present in the water, it can begin to stain the pool. Yellow tones can be a sign of excess iron. Iron can be introduced into a pool by well water or pipe corrosion somewhere in the pool system.

Unlike algae, iron deposits resist flushing and require a lot of elbow grease to remove. A simple water test will confirm the presence of iron in your water.


To correct the problem, allow the chlorine level in your pool to drop to 0 ppm. Lower the pH level of the pool to 6.8 and then add one liter of iron remover for every 5,000 gallons of pool water.

Let the pool sit overnight with the filter running. Raise the pH level back to between 7.2 and 7.8 and then resume your regular chlorination routine. Vacuum up any iron particles that settle at the bottom of your pool during this process.


  • Prevention

Doing a little preventive maintenance is much easier than trying to overcome algae or iron problems. Preventive maintenance will keep your ladders from turning yellow and help manage other potential problems.


  • Clean the pool filter frequently as dirty filters can reintroduce problems you have already solved.
  • Keep an eye on pH and chlorine levels as well, especially if you are filling your pool with well water.
  • Remove debris as soon as it falls into the water, as leaves can carry algae particles into the pool.


Use a clarifier (flocculant) to make it easier to remove yellow algae in your pool steps

If you notice the presence of yellow algae in your pool steps and they haven’t yet started an uncontrolled proliferation, you could use a clarifier (also called flocculant) to eradicate them and save yourself a lot of work. In fact, this additive binds to the floating algae particles, making it easier to vacuum.


On the other hand, if the yellow algae problem in your pool step is more serious, it’s best to follow the full cleaning plan. To quickly get rid of some yellow algae, proceed this way with the clarifier (flocculant).


  • If you have a multiport valve on your pool filter, turn off the pump and turn on the recirculation. This way the clarifier will mix without filtering the water. Read How To Vacuum Pool To Waste Without Multiport Valve
  • Add the recommended dosage of flocculant (can be powder or liquid).
  • Circulate the water for a couple of hours, then turn off the pump and let it sit overnight. The clarifier will bind to the algae, so it will settle to the bottom of the pool.
  • Turn the multi-port valve to Waste mode so that dirty water does not return to the pool.
  • Hooks the backwash hose to the backwash/waste port. Direct the wastewater appropriately.
  • Vacuum the pool. Clean thoroughly to make sure you remove all sediment from the bottom. If the water becomes too cloudy, you should stop and let the particles settle back in before continuing with the vacuuming.
  • Add water as you vacuum because you will remove quite a bit.
  • Immediately after vacuuming, do a double shock treatment to get rid of any remaining algae. It would be best to brush the edges and floor of the pool before doing the shock treatment.
  • Activate the filter.
  • 30 grams of algaecide is worth 2 hours of work
  • You may be wondering why I didn’t tell you to use an algaecide to remove algae from your pool step. Although this product kills algae, it is much more effective as a preventative measure than as a corrective measure.


After thoroughly cleaning your pool, wait until the chlorine drops below five parts per million, then add a dose of algaecide. Brush the pool to remove the last bits of algae that you can’t see. The algaecide will kill them so they can be filtered out.


Cleaning, Sanitizing, and Other Preventive Measures


Proper pool maintenance helps keep algae away. Here are some simple rules:


  • keep the water chemistry balanced, leave the pump on for 8-12 hours a day and perform shock treatments on a regular basis;
  • Before introducing equipment, inflatables, and toys into the pool, make sure they are thoroughly cleaned. You can clean them with a bleach-based detergent or you can create a sanitizing solution by adding a tablespoon of bleach to every 4 liters of water;
  • As mentioned at the beginning, swimsuits can also bring algae into the pool. Obviously, you can’t check your friends, but at least you can wash yours thoroughly, especially if you’ve been swimming in natural waters;
  • if your concrete pool has any cracks (a leak, tile, etc.). fix it. These incisions are a perfect hiding place for algae, as they are shaded and nearly impossible to clean.


Final Thoughts

Even if your pool’s water chemistry is top-notch and you perform regular maintenance, you may still have algae problems.

High humidity levels and wind are just two examples of factors you are unable to control.

The important thing is to take action as soon as you notice algae in your pool because it can quickly grow and proliferate, becoming more difficult to eliminate with each passing day.

Even a small handful of algae spores after cleaning and shock treatment will cause new algae to flourish.

When you notice them, act quickly and aggressively, then make applying algaecide a part of your regular water care routine. Only in this way can you keep algae away forever.

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